PHYSICAL PROPERTIES OF THE AMBIENT PRESSURE DRIED SILICANANOPOROUS AEROGEL BY THE CO-PRECURSOR METHOD

Aerogels are nanoporous with an openpore structure and high surface area. Silica aerogel is a nanostructure material with high surface area, high porosity, low density, low dielectric constant and high thermal insulation values. Because of the low thermal conductivity of aerogel, it is considered as one of the most promising thermal insulating materials for building applications, besides its applications in residential and industrial buildings, aerogel has a geat deal of application areas such as textile, architecture, environment, energy, automobiles, agiculture, medical industry and …. . In this research, we produced aerogel via fast and economic co-precursor method. Sodium silicate and hexamethyldisilazane were used as raw materials. Aging time and raw materials’ molar ratio were studied as the most effective parameters. The samples have been characterized by tape and bulk density, contact angle measurement, N2 adsorptiondesorption BET analyzer, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy. The results indicate that the density of the final product decreases with increasing the amount of sylilating agent. Using this process, it was possible to produce superhydrophobic silica aerogel powders with a contact angle as high as 155.42°, low tapping density of 0.189 g/cm3, high surface area 795.5 m2/g, medium pore diameter of 5.57 nm and thermal conductivity of 0.0205 W/mK.